1. Field of the Invention
This invention relates generally to the field of telephony, and in particular to multi-line telephony over computer networks such as the Internet.
2. Description of Related Art
Traditional communications systems, such as the Public Switched Telephone Network (PSTN), are being combined with digital communications systems. Networks, such as the Internet, have become pervasive, with Internet telephony having been developed for transmitting voice signals via packets.
Internet telephone systems have their own protocols to transfer digital data at an improved rate of speed with adequate clarity. PSTN telephone lines have become over-loaded with information and have not been able to provide reliable, cost-efficient service for the simultaneous transmission of data and voice.
The H.323 standard is an International Telecommunications Union (ITU) standard for packet-based voice and video communications over computer networks, such as local area networks (LANs) and the Internet. ITU Recommendation H.323 describes terminals and equipment which provide this multimedia communications service over packet-based networks (PBN), but which may not provide guaranteed Quality of Service (GQOS), for example, for audio applications. H.323 terminals and equipment may carry real-time audio, video and/or data. According to the standard, support for audio is mandatory, but support for data and video is optional. If data and video transmissions are supported, the ability to use a specified common mode of operation is required, so that all terminals supporting a common type of media may interact and work together.
The packet-based network over which H.323 terminals communicate may implement a point-to-point connection, a single network segment, or a complex network having multiple segments with complex topologies. H.323 terminals may communicate with terminals defined by other standards, e.g., H.310 terminals on a broadband integrated service digital network (B-ISDN), H.320 terminals on a narrowband integrated services digital network (N-ISDN), H.321 terminals on B-ISDN, H.322 terminals on GQOS LANs, H.324 terminals on general switched telephone networks (GSTNs) and wireless networks, V.70 terminals on GSTNs, and voice terminals on GSTNs or ISDNs through the use of gateways. H.323 terminals may be integrated into personal computers or implemented in stand-alone devices, such as video telephones.
A need exists for a network which moves data faster than the conventional PSTN, and provides more real-time response, better quality of service (QOS), and better transmissions. It would be advantageous for such a network to interact and provide a liaison with a PSTN to facilitate functions within the network as well as to provide improved functionality over the current telephone communication system. Such a system is described in co-pending U.S. patent application Ser. No. 60/105,320 (Attorney Docket Number 98-808) of Gardell et al. entitled xe2x80x9cA HIGH SPEED COMMUNICATIONS SYSTEM OPERATING OVER A COMPUTER NETWORKxe2x80x9d, and filed concurrently herewith, the disclosure of which is incorporated herein by reference.
A need also exists for a network capable of increasing transmission of telephone data up to 30 or 40 phone conversations on a single wire.
Heretofore, H.323-based networks have been implemented by connecting such terminals through conventional telephone lines of the PSTN, which is thus limited by the bandwidth and performance characteristics of the PSTN. A need exists for implementing an H.323-based network over faster communication channels using, for example, interface equipment and protocols for connecting H.323 terminals over high speed communication channels, such as Internet-based systems.
It is one aspect of our invention that improved packet-based communications may be achieved for performing multi-line telephony with better transmission characteristics, such as enhanced transmission speed, over traditional twisted-pair wire connections to provide H.323-based network operations. Utilizing digital subscriber line access multiplexer technology, the present invention is capable of maintaining multiple, concurrent, independent telephone calls over a single telephone line. The invention connects two or more callers to a single end-point and multiplexes data packets from the two or more callers to the receiving end-point. With the high transmission rates provided by ADSL technology, the voice data from multiple callers can be delivered to the end-point over a single subscriber line.
In accordance with our invention, a multi-line telephony system includes software and hardware to provide the ability to deliver multiple concurrent telephone conversations to a customer premises via a single traditional twisted-pair communications connection, and also to support telephone services via a traditional dial-up connection. The system includes a point-of-presence entity which is programmed to effect a simultaneous connection between the customer premises and at least two other connecting telephone devices, utilizing packet-based technology and ADSL transmission rates.